Current perpendicular to plane (CPP) GMR structure having vanadium doped, AP coupled, multi-layered pinned structure

Abstract

A current perpendicular to plane (CPP) giant magnetoresistive (GMR) sensor having an antiparallel coupled (AP coupled) pinned layer structure wherein the pinning layer have a greatly reduced negative contribution to dR. The pinned layer structure includes a first a first set of magnetic layers such as CoFe and a second set of magnetic layer comprising CoFeV that are antiparallel coupled with the first set of magnetic layers. The magnetic layers of the pinned layer structure alternate between a one of the first set of magnetic layers (eg. CoFe) and one of the second set of magnetic layers (CoFeV). The magnetic layers of the first set contribute to the GMR of the sensor and provide a positive magnetostriction that assists with the pinning of the pinned layer structure. The magnetic layers of the second set contribute pinning, but do not contribute to GMR. The presence of V in the second set of greatly reduces the negative contribution to dR that would otherwise be provided by these pinning layers of the second set by reducing the spin dependent electron scattering through these layers.

Description

FIELD OF THE INVENTION [0001] The present invention relates to a current perpendicular to plane (CPP) giant magnetoresistive (GMR) sensor and more particularly to a sensor having improved GMR effect through the use of a multi-layered pinned structure having layers including vanadium (V). BACKGROUND OF THE INVENTION [0002] The heart of a computer is an assembly that is referred to as a magnetic disk drive. The magnetic disk drive includes a rotating magnetic disk, write and read heads that are suspended by a suspension arm adjacent to a surface of a rotating magnetic disk and an actuator that swings the suspension arm to place the read and write heads over selected circular tracks on the rotating disk. The read and write heads are directly located on a slider that has an air bearing surface (ABS). The suspension arm biases the slider into contact with the surface of the disk when the disk is not rotating but, when the disk rotates, air is swirled by the rotating disk. When the slider...

AI Technical Summary

Benefits of technology

[0015] The first set of magnetic layers contributes to the GMR of the sensor as well as providing a desired positive magnetostriction, which contributes to pinning of the magnetic moments of the pinned layer structure. The second set of magnetic layers, having magnetic moments that are 180 out of phase with the first set of magnetic layers would provide an undesirable subtractive dR, were it not for the presence of V in these layers. The presence of V in the second set of magnetic layers greatly reduces the spin dependent scattering from these layers, thereby minimizing the negative dR from these layes.

[0016] The presence of V, however, advantageously does not reduce the magnetic moment of these layers. In addition, the presence of V in the second set of magnetic layers increases the positive magnetostriction of these layer, which further contributes to pinning.

[0017] The multilayer structure of the present invention further promotes pinning by providing additional magnetostatic coupling between the AP coupled magnetic layers of the first and second set of magnetic layers. As discussed in the Background of the Invention, a thicker pinned layer provides improved dR, but also results in decreased pinning. Constructing the pinned layer structure with multiple pinned and pinning layers advantageously provides the dR of a thicker pinned layer structure while also maintainging strong pinning.

[0018] The multilayer structure also advantageously increases dR (GMR) of the sensor by providing additional spin dependent scattering interfaces for each of the plurality of magnetic pinned layers (the first set of magnetic layers). This additional dR from multiple AP coupling layers would not be practical without the presence of V in the pinning layers to reduce the negative dR, because the negative dR from the pinning layers would negate any improvement in dR provided by the increased spin dependent scattering from the increased number of interfaces.

Problems solved by technology

In addition, the presence of V in the second set of magnetic layers increases the positive magnetostriction of these layer, which further contributes to pinning.

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